Porous nanohybrids of cationic Mg-Al-LDH 2D nanosheets and anionic polyoxometalate (POM, V10O286- and W7O246-) 0D nanoclusters are synthesized by an exfoliation-reassembling process. The electrostatically derived reassembling between two kinds of nanostructures yields a layer-by-layer-ordered intercalation structure with porous structures composed of mesopores and micropores. The hybridization with POM leads to the remarkable enhancement of CO2 adsorption capacity (adsorptivity) of Mg-Al-LDH by about 10-fold. Of prime importance is that the CO2 adsorptivity of the nanohybrid is strongly dependent on the type of guest POM species, strongly suggesting that the CO2 adsorptivity of the LDH-based nanohybrid materials can be optimized by ones selection of guest species. The present study clearly demonstrates that the exfoliation-reassembling method is quite effective at enabling synthesis of new LDH nanosheet-based hybrid materials with improved CO2 adsorption capabilities.